Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.645
Filtrar
1.
Arch Microbiol ; 206(4): 148, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38462558

RESUMO

Pseudomonas aeruginosa is an opportunistic gram-negative pathogenic microorganism that poses a significant challenge in clinical treatment. Antibiotics exhibit limited efficacy against mature biofilm, culminating in an increase in the number of antibiotic-resistant strains. Therefore, novel strategies are essential to enhance the effectiveness of antibiotics against Pseudomonas aeruginosa biofilms. D-histidine has been previously identified as a prospective anti-biofilm agent. However, limited attention has been directed towards its impact on Pseudomonas aeruginosa. Therefore, this study was undertaken to explore the effect of D-histidine on Pseudomonas aeruginosa in vitro. Our results demonstrated that D-histidine downregulated the mRNA expression of virulence and quorum sensing (QS)-associated genes in Pseudomonas aeruginosa PAO1 without affecting bacterial growth. Swarming and swimming motility tests revealed that D-histidine significantly reduced the motility and pathogenicity of PAO1. Moreover, crystal violet staining and confocal laser scanning microscopy demonstrated that D-histidine inhibited biofilm formation and triggered the disassembly of mature biofilms. Notably, D-histidine increased the susceptibility of PAO1 to amikacin compared to that in the amikacin-alone group. These findings underscore the efficacy of D-histidine in combating Pseudomonas aeruginosa by reducing biofilm formation and increasing biofilm disassembly. Moreover, the combination of amikacin and D-histidine induced a synergistic effect against Pseudomonas aeruginosa biofilms, suggesting the potential utility of D-histidine as a preventive strategy against biofilm-associated infections caused by Pseudomonas aeruginosa.


Assuntos
Amicacina , Infecções por Pseudomonas , Humanos , Amicacina/farmacologia , Amicacina/metabolismo , Amicacina/uso terapêutico , Pseudomonas aeruginosa , Histidina/farmacologia , Histidina/metabolismo , Histidina/uso terapêutico , Biofilmes , Percepção de Quorum , Antibacterianos/química , Infecções por Pseudomonas/microbiologia , Fatores de Virulência/metabolismo
2.
Sci Rep ; 14(1): 6883, 2024 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-38519558

RESUMO

We developed a reporter system based on simultaneous expression of two fluorescent proteins: GFP as a reporter of the capacity of protein synthesis and mutated mScarlet-I as a reporter of translational errors. Because of the unique stop codons or frameshift mutations introduced into the mScarlet-I gene, red fluorescence was produced only after a mistranslation event. These reporters allowed us to estimate mistranslation at a single cell level using either flow cytometry or fluorescence microscopy. We found that laboratory strains of Escherichia coli are more prone to mistranslation compared to the clinical isolates. As relevant for uropathogenic E. coli, growth in human urine elevated translational frameshifting compared to standard laboratory media, whereas different standard media had a small effect on translational fidelity. Antibiotic-induced mistranslation was studied by using amikacin (aminoglycoside family) and azithromycin (macrolide family). Bactericidal amikacin induced preferably stop-codon readthrough at a moderate level. Bacteriostatic azithromycin on the other hand induced both frameshifting and stop-codon readthrough at much higher level. Single cell analysis revealed that fluorescent reporter-protein signal can be lost due to leakage from a fraction of bacteria in the presence of antibiotics, demonstrating the complexity of the antimicrobial activity.


Assuntos
Antibacterianos , Mutação da Fase de Leitura , Humanos , Antibacterianos/farmacologia , Azitromicina/farmacologia , Amicacina , Escherichia coli/genética , Códon de Terminação/genética , Biossíntese de Proteínas
3.
Antimicrob Resist Infect Control ; 13(1): 28, 2024 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-38433212

RESUMO

BACKGROUND: Aeromonas hydrophila infections can cause gastrointestinal symptoms such as diarrhea; however, deep infections are rarely reported. Outbreaks of A. hydrophila are reported more frequently in fish, poultry, and snakes than in humans. This study aimed to track clonal relatedness of deep infections caused by A. hydrophila using whole genome sequencing (WGS). METHODS: We collected three isolates of A. hydrophila in July 19 to August 29, 2019, from patients that underwent spine surgery. Accurate species identification was performed using whole-genome average nucleotide identity (ANI). Antimicrobial susceptibility testing was performed using a VITEK 2 automated AST-N334 Gram-negative susceptibility card system. Antimicrobial resistance and virulence genes were identified using the Comprehensive Antibiotic Resistance Database and Virulence Factor Database VFanalyzer. RESULTS: All three isolates were identified as A. hydrophila based on ANI and multilocus sequence typing analysis revealed that A. hydrophila belonged to a novel sequence type (ST1172). All three isolates were susceptible to amikacin and levofloxacin; however, they were resistant to piperacillin/tazobactam, ceftriaxone, cefuroxime, cefoxitin, and imipenem. Isolate 19W05620 (patient 3) showed increased ceftazidime resistance (minimum inhibitory concentration ≥ 64 µg/mL). All three isolates possessed the same chromosomally encoded ß-lactamases, including blaOXA-724 (ß-lactamase), imiH (metallo-ß-lactamase), and blaMOX-13 (AmpC) in plasmids. CONCLUSIONS: Our study validated the transmission of a novel carbapenem-resistant A. hydrophila sequence type (ST1172) in patients that underwent spine surgery. Control measures should be developed to prevent dissemination of A. hydrophila in the hospital setting.


Assuntos
Aeromonas hydrophila , Anti-Infecciosos , Animais , Humanos , Aeromonas hydrophila/genética , Amicacina , Carbapenêmicos , beta-Lactamases
4.
Ann Clin Microbiol Antimicrob ; 23(1): 14, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38350903

RESUMO

PURPOSE: This study aimed to characterise the whole-genome structure of two clinical Klebsiella pneumoniae strains co-harbouring mcr-8.1 and tmexCD1-toprJ1, both resistant to colistin and tigecycline. METHODS: K. pneumoniae strains TGC-02 (ST656) and TGC-05 (ST273) were isolated from urine samples of different patients hospitalised at separate times in 2021. Characterisation involved antimicrobial susceptibility testing (AST), conjugation assays, whole-genome sequencing (WGS), and bioinformatics analysis. Comparative genomic analysis was conducted on mcr-8.1-carrying and tmexCD1-toprJ1-carrying plasmids. RESULTS: Both K. pneumoniae isolates displayed a multidrug-resistant phenotype, exhibiting resistance or reduced susceptibility to ampicillin, ampicillin/sulbactam, cefazolin, aztreonam, amikacin, gentamicin, tobramycin, ciprofloxacin, levofloxacin, nitrofurantoin, trimethoprim/sulfamethoxazole, apramycin, tigecycline and colistin. WGS analysis revealed that clinical strain TGC-02 carried the TmexCD1-toprJ1 gene on a 200-Kb IncFII/IncFIB-type plasmid, while mcr-8 was situated on a 146-Kb IncFII-type plasmid. In clinical strain TGC-05, TmexCD1-toprJ1 was found on a 300-Kb IncFIB/IncHI1B/IncR-type plasmid, and mcr-8 was identified on a 137-Kb IncFII/IncFIA-type plasmid. Conjugation experiments assessed the transferability of these plasmids. While transconjugants were not obtained for TGC-05 despite multiple screening with tigecycline or colistin, pTGC-02-tmex and pTGC-02-mcr8 from clinical K. pneumoniae TGC-02 demonstrated self-transferability through conjugation. Notably, the rearrangement of pTGC-02-tmex and pTGC-02-mcr8 via IS26-based homologous recombination was observed. Moreover, the conjugative and fusion plasmids of the transconjugant co-harboured the tmexCD1-toprJ1 gene cluster and mcr-8.1, potentially resulting from IS26-based homologous recombination. CONCLUSION: The emergence of colistin- and tigecycline-resistant K. pneumoniae strains is concerning, and effective surveillance measures should be implemented to prevent further dissemination.


Assuntos
Amicacina , Colistina , Humanos , Colistina/farmacologia , Tigeciclina , Ampicilina , Aztreonam , Klebsiella pneumoniae/genética , Plasmídeos/genética , Antibacterianos/farmacologia
9.
Microbiol Spectr ; 12(2): e0322223, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38236037

RESUMO

Mycobacterium abscessus pulmonary disease is increasing in prevalence globally, particularly for individuals with cystic fibrosis. These infections are challenging to treat due to a high rate of resistance. Amikacin is critical to treatment, but the development of toxicity, amikacin resistance, and treatment failure are significant challenges. Amikacin has been characterized previously as peak-dependent and extended-interval dosing is commonly used. In our hollow fiber infection model of M. abscessus, amikacin exhibited time-dependent rather than the expected peak-dependent pharmacodynamics. Humanized amikacin exposures with more frequent, short-interval dosing (continuous infusion or every 12 hours) yielded improved microbiological response compared to extended-interval dosing (every 24 hours or 1-3 times per week). Short-interval dosing inhibited growth with a mean (SD) maximum Δlog10 colony forming units of -4.06 (0.52), significantly more than extended-interval dosing (P = 0.0013) every 24 hours, -2.40 (0.58), or 1-3 times per week, -2.39 (0.38). Growth recovery, an indicator of resistance emergence, occurred at 6.56 (0.70) days with short-interval dosing but was significantly earlier with extended-interval dosing (P = 0.0032) every 24 hours, 3.88 (0.85) days, and 1-3 times per week, 3.27 (1.72) days. Microbiological response correlated best with the pharmacodynamic index of %T > minimum inhibitory concentration (MIC), with an EC80 for growth inhibition of ~40%T > MIC. We used a previously published population model of amikacin to determine the probability of achieving 40%T > MIC and show that current dosing strategies are far below this target, which may partially explain why treatment failure remains so high for these infections. These data support a cautious approach to infrequent amikacin dosing for the treatment of M. abscessus.IMPORTANCEPulmonary disease caused by Mycobacterium abscessus complex (MABSC) is increasing worldwide, particularly in patients with cystic fibrosis. MABSC is challenging to treat due to high levels of antibiotic resistance. Treatment requires 2-4 antibiotics over more than 12 months and has a significant risk of toxicity but still fails to eradicate infection in over 50% of patients with cystic fibrosis. Antibiotic dosing strategies have been largely informed by common bacteria such as Pseudomonas aeruginosa. The "pharmacodynamic" effects of amikacin, a backbone of MABSC treatment, were thought to be related to maximum "peak" drug concentration, leading to daily or three times weekly dosing. However, we found that amikacin MABSC kill and growth recovery, an indicator of antibiotic resistance, are dependent on how long amikacin concentrations are above the minimum inhibitory concentration, not how high the peak concentration is. Therefore, we recommend a re-evaluation of amikacin dosing to determine if increased frequency can improve efficacy.


Assuntos
Fibrose Cística , Infecções por Mycobacterium não Tuberculosas , Mycobacterium abscessus , Humanos , Amicacina , Fibrose Cística/microbiologia , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Infecções por Mycobacterium não Tuberculosas/microbiologia
10.
BMC Res Notes ; 17(1): 38, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38273327

RESUMO

OBJECTIVES: Urinary tract infections (UTIs) are very common infections in humans, and Escherichia coli (E. coli) is the commonest pathogen leading to UTIs. The generation of beta-lactamase enzymes in this bacterium results in its resistance against many antibiotics. This study compares three doses of amikacin on alternate days with a daily dose of meropenem in the same period for the treatment of UTIs with E. coli in a double-blind clinical trial. METHODS: The current double-blind clinical trial compares three doses of amikacin on alternate days with a daily dose of meropenem in the same period for the treatment of UTIs with E. coli. The patients were assigned to two groups: Intervention (receiving a single dose of amikacin once a day at 48-h intervals for a week, three doses) and control (receiving meropenem for 1/TDS for a week). RESULTS: The E. coli infection frequency was 61 (21 cases of non-ESBL and 40 cases of ESBL-positive infections) and the frequency of the other infections was 52 (46%). In the patients with ESBL E. coli infection, ciprofloxacin (21; 70%) showed the highest antibiotic resistance, and nitrofurantoin (33; 91.7%) showed the highest sensitivity. The baseline variables between the control and intervention groups indicated no significant difference (p > 0.05). The frequency of signs and symptoms showed no significant difference between the amikacin and meropenem groups in the first 24 h and the first week. In the second week of follow-up, no clinical signs or symptoms were observed in the two groups. CONCLUSION: The results of this study showed that treatment with amikacin, 1 g q48h, for one week (three doses) has the same result as meropenem, 1 g q8h, for one week (21 doses). The results are the same for the treatment of UTIs with ESBL positive and ESBL negative. Amikacin can be used once every 48 h to treat UTIs, is less expensive and can be administered on an outpatient basis. TRIAL REGISTRATION: This study was registered in the Iranian Registry of Clinical Trials (IRCT) with ID number: IRCT20170417033483N2 on the date 2018-02-13.


Assuntos
Infecções por Escherichia coli , Infecções Urinárias , Humanos , Amicacina/administração & dosagem , Antibacterianos/administração & dosagem , beta-Lactamases , Método Duplo-Cego , Escherichia coli , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Irã (Geográfico) , Meropeném/administração & dosagem , Testes de Sensibilidade Microbiana , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/microbiologia
11.
mBio ; 15(2): e0316523, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38236031

RESUMO

Hospital-acquired pneumonia (HAP) is a leading cause of morbidity and mortality, commonly caused by Pseudomonas aeruginosa. Meropenem is a commonly used therapeutic agent, although emergent resistance occurs during treatment. We used a rabbit HAP infection model to assess the bacterial kill and resistance pharmacodynamics of meropenem. Meropenem 5 mg/kg administered subcutaneously (s.c.) q8h (±amikacin 3.33-5 mg/kg q8h administered intravenously[i.v.]) or meropenem 30 mg/kg s.c. q8h regimens were assessed in a rabbit lung infection model infected with P. aeruginosa, with bacterial quantification and phenotypic/genotypic characterization of emergent resistant isolates. The pharmacokinetic/pharmacodynamic output was fitted to a mathematical model, and human-like regimens were simulated to predict outcomes in a clinical context. Increasing meropenem monotherapy demonstrated a dose-response effect to bacterial kill and an inverted U relationship with emergent resistance. The addition of amikacin to meropenem suppressed the emergence of resistance. A network of porin loss, efflux upregulation, and increased expression of AmpC was identified as the mechanism of this emergent resistance. A bridging simulation using human pharmacokinetics identified meropenem 2 g i.v. q8h as the licensed clinical regimen most likely to suppress resistance. We demonstrate an innovative experimental platform to phenotypically and genotypically characterize bacterial emergent resistance pharmacodynamics in HAP. For meropenem, we have demonstrated the risk of resistance emergence during therapy and identified two mitigating strategies: (i) regimen intensification and (ii) use of combination therapy. This platform will allow pre-clinical assessment of emergent resistance risk during treatment of HAP for other antimicrobials, to allow construction of clinical regimens that mitigate this risk.IMPORTANCEThe emergence of antimicrobial resistance (AMR) during antimicrobial treatment for hospital-acquired pneumonia (HAP) is a well-documented problem (particularly in pneumonia caused by Pseudomonas aeruginosa) that contributes to the wider global antimicrobial resistance crisis. During drug development, regimens are typically determined by their sufficiency to achieve bactericidal effect. Prevention of the emergence of resistance pharmacodynamics is usually not characterized or used to determine the regimen. The innovative experimental platform described here allows characterization of the emergence of AMR during the treatment of HAP and the development of strategies to mitigate this. We have demonstrated this specifically for meropenem-a broad-spectrum antibiotic commonly used to treat HAP. We have characterized the antimicrobial resistance pharmacodynamics of meropenem when used to treat HAP, caused by initially meropenem-susceptible P. aeruginosa, phenotypically and genotypically. We have also shown that intensifying the regimen and using combination therapy are both strategies that can both treat HAP and suppress the emergence of resistance.


Assuntos
Infecção Hospitalar , Pneumonia Associada a Assistência à Saúde , Infecções por Pseudomonas , Animais , Humanos , Coelhos , Meropeném/farmacologia , Pseudomonas aeruginosa , Amicacina/farmacologia , Amicacina/uso terapêutico , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , Pneumonia Associada a Assistência à Saúde/tratamento farmacológico , Testes de Sensibilidade Microbiana
12.
Int J Biol Macromol ; 260(Pt 1): 129529, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38237819

RESUMO

Dynamic antibacterial polysaccharide prodrug hydrogels are in great demand for treatment of wound infection owing to their unique advantages such as excellent biocompatibility, superior antimicrobial property as well as favorable wound healing capacity. Herein, this work highlights the successful development of a dynamic carboxymethyl chitosan (CMC) prodrug hydrogel, which is facilely constructed through Schiffer base reaction between antibacterial components (amikacin and CMC) and crosslinker (dialdehyde PEG). Moderate dynamic imine linkages endow the hydrogel with excellent injectable and self-healing capability as well as targeted on-demand drug release in slightly alkaline condition at infected wound. All ingredients and their strong intermolecular interactions endow the hydrogel with favorable swelling and moisture retention capability. Moreover, the covalent and non-covalent interactions also endow the hydrogel with superior adhesion and mechanical property. These attractive characteristics enable hydrogel to effectively kill pathogens, promote wound healing and reduce side effects of amikacin. Thereby, such a dynamic CMC prodrug hydrogel may open a new avenue for a robust therapy on wound infection, greatly advancing their use in clinics.


Assuntos
Quitosana , Infecção dos Ferimentos , Humanos , Quitosana/farmacologia , Amicacina , Hidrogéis/farmacologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecção dos Ferimentos/tratamento farmacológico
13.
Antimicrob Agents Chemother ; 68(3): e0139423, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38289076

RESUMO

Amikacin is an FDA-approved aminoglycoside antibiotic that is commonly used. However, validated dosage regimens that achieve clinically relevant exposure profiles in mice are lacking. We aimed to design and validate humanized dosage regimens for amikacin in immune-competent murine bloodstream and lung infection models of Acinetobacter baumannii. Plasma and lung epithelial lining fluid (ELF) concentrations after single subcutaneous doses of 1.37, 13.7, and 137 mg/kg of body weight were simultaneously modeled via population pharmacokinetics. Then, humanized amikacin dosage regimens in mice were designed and prospectively validated to match the peak, area, trough, and range of plasma concentration profiles in critically ill patients (clinical dose: 25-30 mg/kg of body weight). The pharmacokinetics of amikacin were linear, with a clearance of 9.93 mL/h in both infection models after a single dose. However, the volume of distribution differed between models, resulting in an elimination half-life of 48 min for the bloodstream and 36 min for the lung model. The drug exposure in ELF was 72.7% compared to that in plasma. After multiple q6h dosing, clearance decreased by ~80% from the first (7.35 mL/h) to the last two dosing intervals (~1.50 mL/h) in the bloodstream model. Likewise, clearance decreased by 41% from 7.44 to 4.39 mL/h in the lung model. The humanized dosage regimens were 117 mg/kg of body weight/day in mice [administered in four fractions 6 h apart (q6h): 61.9%, 18.6%, 11.3%, and 8.21% of total dose] for the bloodstream and 96.7 mg/kg of body weight/day (given q6h as 65.1%, 16.9%, 10.5%, and 7.41%) for the lung model. These validated humanized dosage regimens and population pharmacokinetic models support translational studies with clinically relevant amikacin exposure profiles.


Assuntos
Amicacina , Pneumonia , Humanos , Animais , Camundongos , Amicacina/farmacocinética , Antibacterianos/farmacocinética , Pulmão , Pneumonia/tratamento farmacológico , Peso Corporal
14.
Int J Antimicrob Agents ; 63(2): 107089, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38218322

RESUMO

OBJECTIVES: Aminoglycoside resistance in bacteria is typically conferred by specific drug-modifying enzymes. Infrequently, such resistance is achieved through 16S ribosomal RNA methyltransferases, such as NpmA and KamB encoded by Escherichia coli and Streptoalloteichus tenebrarius, respectively. These enzymes are not widespread and have not been described in Nocardia species to date. METHODS: We report the genomic mining of 18 Nocardia wallacei isolates that were found to be specifically and substantially resistant to amikacin. RESULTS: We identified a gene coding for a protein with very distant homology to NpmA and KamB. However, 3-D modeling revealed that the tertiary structure of these three proteins was highly similar. Cloning and expressing this gene in two susceptible bacteria Nocardia asteroides, and Mycobacterium smegmatis (another Actinobacterium) led to high-level, pan-aminoglycoside resistance in both cases. We named this gene warA (Wallacei Amikacin Resistance A). CONCLUSIONS: This is the first description and experimental characterization of a gene of this family in Nocardia, and the first demonstration that such activity could lead to pan-aminoglycoside resistance in Mycobacteria as well. The discovery of this novel gene has important biotechnology and clinical implications.


Assuntos
Mycobacterium , Nocardia , Aminoglicosídeos/metabolismo , Amicacina/farmacologia , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Nocardia/genética , Nocardia/metabolismo , Escherichia coli/genética , Mycobacterium/genética , Mycobacterium/metabolismo , RNA Ribossômico 16S/genética , Farmacorresistência Bacteriana/genética
15.
Respir Investig ; 62(2): 284-290, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38277865

RESUMO

BACKGROUND: CONVERT, a randomized, active-controlled, global, Phase 3 trial demonstrated that patients with treatment-refractory Mycobacterium avium complex (MAC) pulmonary disease were more likely to achieve culture conversion with amikacin liposome inhalation suspension (ALIS) plus guideline-based therapy (GBT) versus those continuing on GBT alone. This subgroup analysis reports the efficacy and safety of ALIS in Japanese patients enrolled in CONVERT. METHODS: Japanese patients aged ≥20 years with treatment-refractory MAC pulmonary disease from Japanese sites were included. Patients were randomized to receive once-daily 590 mg ALIS + GBT or GBT alone; patients converting by Month 6 remained in the study to complete 12-month treatment followed by a 12-month off-treatment period. Nonconverters exited the study at Month 8. The primary endpoint was the proportion of patients achieving culture conversion by Month 6. RESULTS: Of the 59 Japanese patients screened, 48 were randomized to receive ALIS + GBT (n = 34) or GBT alone (n = 14), and 41/48 (85.4 %) were women. The mean (standard deviation) age of patients was 64.5 (8.6) years, and 83.3 % of patients had bronchiectasis at baseline. By Month 6, sputum culture conversion was cumulatively achieved in 9/34 (26.5 %) patients receiving ALIS + GBT versus none receiving GBT alone. Treatment-emergent adverse events were reported in 94.1 % and 100.0 % of patients receiving ALIS + GBT and GBT alone, respectively. No deaths were reported. CONCLUSIONS: The efficacy observed in the Japanese subpopulation was largely consistent with that in the overall CONVERT study population, with more patients achieving culture conversion with ALIS + GBT versus GBT alone. Safety profiles were similar between the overall population and the Japanese subpopulation. CLINICAL TRIAL REGISTRATION: NCT02344004.


Assuntos
Pneumopatias , Infecção por Mycobacterium avium-intracellulare , Feminino , Humanos , Masculino , Amicacina/efeitos adversos , Antibacterianos/efeitos adversos , Japão , Lipossomos/uso terapêutico , Pneumopatias/induzido quimicamente , Complexo Mycobacterium avium , Infecção por Mycobacterium avium-intracellulare/tratamento farmacológico , Pessoa de Meia-Idade , Idoso
16.
Antimicrob Agents Chemother ; 68(2): e0121623, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38214514

RESUMO

The growing threat of antibiotic-resistant bacterial pathogens necessitates the development of alternative antimicrobial approaches. This is particularly true for chronic wound infections, which commonly harbor biofilm-dwelling bacteria. A novel electrochemical bandage (e-bandage) delivering low-levels of hypochlorous acid (HOCl) was evaluated against Pseudomonas aeruginosa murine wound biofilms. 5 mm skin wounds were created on the dorsum of mice and infected with 106 colony-forming units (CFU) of P. aeruginosa. Biofilms were formed over 2 days, after which e-bandages were placed on the wound beds and covered with Tegaderm. Mice were administered Tegaderm-only (control), non-polarized e-bandage (no HOCl production), or polarized e-bandage (using an HOCl-producing potentiostat), with or without systemic amikacin. Purulence and wound areas were measured before and after treatment. After 48 hours, wounds were harvested for bacterial quantification. Forty-eight hours of polarized e-bandage treatment resulted in mean biofilm reductions of 1.4 log10 CFUs/g (P = 0.0107) vs non-polarized controls and 2.2 log10 CFU/g (P = 0.004) vs Tegaderm-only controls. Amikacin improved CFU reduction in Tegaderm-only (P = 0.0045) and non-polarized control groups (P = 0.0312) but not in the polarized group (P = 0.3876). Compared to the Tegaderm-only group, there was less purulence in the polarized group (P = 0.009). Wound closure was neither impeded nor improved by either polarized or non-polarized e-bandage treatment. Concurrent amikacin did not impact wound closure or purulence. In conclusion, an HOCl-producing e-bandage reduced P. aeruginosa in wound biofilms with no impairment in wound healing, representing a promising antibiotic-free approach for addressing wound infection.


Assuntos
Infecções por Pseudomonas , Infecção dos Ferimentos , Animais , Camundongos , Pseudomonas aeruginosa , Ácido Hipocloroso , Amicacina , Infecções por Pseudomonas/microbiologia , Infecção dos Ferimentos/microbiologia , Bandagens , Antibacterianos , Biofilmes
17.
Mymensingh Med J ; 33(1): 125-132, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38163783

RESUMO

Wound infection is one of the most important causes of morbidity and mortality worldwide. The aim of this study was to identify the organisms and their sensitivity pattern from wound infection patients attending in a tertiary care hospital in Dhaka city. This cross-sectional study was carried out in a total of 240 aseptically collected wound swab samples from wound infection suspected patients visiting Bangladesh Medical College Hospital, Dhaka, Bangladesh were analyzed from July 2017 to June 2019. Bacteriological culture of the samples, colony morphology, Gram's staining, and biochemical tests were done following standard microbiological techniques. The antimicrobial susceptibility testing was performed by modified Kirby-Bauer disc diffusion technique following clinical and laboratory standards institute guidelines. Out of 240 wound swab samples from suspected patients of wound infection, 126(52.5%) showed bacterial growth whereas 114(47.5%) were culture negative. No sample yielded more than one organism. Among 126 culture positive cases 75(59.52%) were male and 51(40.48%) were female. The higher rate of bacterial infections 26.19% was noted in the age group of 21-30 years, followed by the age group of 31-40 years, 41-50 years, 51-60 years. Among 126 culture positive cases, 74.6% were Gram negative and 25.4% were Gram positive bacteria. Out of total 126 isolates, E. coli was the most prevalent pathogen 31(24.60%) followed by Staphylococcus aureus 29(23.01%); Pseudomonas 27(21.43%); Klebsiella 18(14.29%); Enterobacter 12(9.52%); Acinetobacter 4(3.17%), while Coagulase negative Staphylococcus 3(2.38%) and Proteus 2(1.59%) were least detected isolates in wound swab. Highly effective antibiotics against Staph aureus were vancomycin 100.0%; imipenem 100.0%; linezolid 100.0% and meropenem 89.65%. Amikacin; gentamicin; netilmicin; imipenem and meropenem showed higher sensitivity in E coli, Klebsiella and Enterobacter species. Colistin was 88.88% effective against Pseudominas spp. followed by imipenem 81.48%, piperacillin-tazobactam 77.78%, meropenem 70.37% and amikacin 51.85%. Acinetobacter spp. showed 75.0% and 50.0% sensitivity to netilmicin and colistin respectively. Injectable and reserve drugs were sensitive to bacterial populations among patients of wound infections in our hospital. It is a wake-up call for clinician to treat wound infections. To prevent the increase resistance to antibiotics, it is necessary to avoid the administration of uncontrolled and unnecessary antibiotics available.


Assuntos
Colistina , Infecção dos Ferimentos , Humanos , Masculino , Feminino , Adulto Jovem , Adulto , Colistina/farmacologia , Escherichia coli , Netilmicina/farmacologia , Meropeném/farmacologia , Amicacina/farmacologia , Centros de Atenção Terciária , Estudos Transversais , Bangladesh/epidemiologia , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia , Staphylococcus aureus , Testes de Sensibilidade Microbiana , Imipenem/farmacologia
18.
BMC Infect Dis ; 24(1): 118, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38262940

RESUMO

OBJECTIVES: This study aimed to measure the prevalence of resistance to antimicrobial agents, and explore the risk factors associated with drug resistance by using nontuberculous Mycobacteria (NTM) isolates from China. METHODS: A total of 335 NTM isolates were included in our analysis. Broth dilution method was used to determine in vitro drug susceptibility of NTM isolates. RESULTS: Clarithromycin (CLA) was the most potent drug for Mycobacterium intracellulare (MI). The resistance rate of 244 MI isolates to CLA was 21%, yielding a minimum inhibitory concentrations (MIC)50 and MIC90 of 8 and 64 mg/L, respectively. 51% of 244 MI isolates exhibited resistance to amikacin (AMK). For 91 Mycobacterium abscessus complex (MABC) isolates, 6 (7%) and 49 (54%) isolates were categorized as resistant to CLA at day 3 and 14, respectively. The resistance rate to CLA for Mycobacterium abscessus subspecies abscessus (MAA) was dramatically higher than that for Mycobacterium abscessus subspecies massiliense (MAM). Additionally, the percentage of patients presenting fever in the CLA-susceptible group was significantly higher than that in the CLA-resistant group. CONCLUSIONS: Our data demonstrate that approximate one fifth of MI isolates are resistant to CLA. We have identified a higher proportion of CLA-resistant MAA isolates than MAM. The patients caused by CLA-resistant MI are at low risk for presenting with fever relative to CLA-susceptible group.


Assuntos
Mycobacterium abscessus , Micobactérias não Tuberculosas , Humanos , Complexo Mycobacterium avium , China , Amicacina , Claritromicina , Febre
19.
PLoS One ; 19(1): e0295528, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38271353

RESUMO

OBJECTIVES: To examine spatial effects in neonatal care, we conducted a retrospective cohort study to investigate the geographical distribution of antimicrobial exposure among very preterm and very low birth weight infants in Japan. STUDY DESIGN: We utilized a nationwide claims database in Japan to extract prescriptions of injectable antimicrobials for 41,423 very preterm and very low birth weight infants admitted within the first two days of life from April 2010 to March 2021. We identified frequently prescribed antimicrobials, revealed early neonatal exposure and neonatal exposure to each antimicrobial agent by 47 prefectures in Japan, and evaluated their spatial autocorrelation using global and local Moran's I statistics. We then scrutinized regional disparities in antimicrobial drug prescriptions. RESULTS: The top 10 antimicrobials prescribed to very preterm and very low birth weight infants in Japan were ampicillin, amikacin, gentamicin, cefotaxime, fluconazole, ampicillin combination, micafungin, cefmetazole, cefazolin, and vancomycin. We identified northern cold spots for fluconazole exposure and southern hot spots for ampicillin, amikacin, gentamicin, and cefmetazole exposure. Geographical heterogeneity in the selection of antibacterial and antimycotic agents was observed. CONCLUSION: Our study revealed the geographical distribution of antimicrobial exposure among very preterm and very low birth weight infants in Japan, thus disclosing its spatial effects. Further research addressing the spatial effects of neonatal care is needed to understand how drug exposure affects the outcomes of preterm infants.


Assuntos
Anti-Infecciosos , Eritropoetina , Lactente , Recém-Nascido , Humanos , Lactente Extremamente Prematuro , Estudos Retrospectivos , Amicacina , Japão , Cefmetazol , Fluconazol/uso terapêutico , Recém-Nascido de muito Baixo Peso , Ampicilina , Gentamicinas
20.
Antimicrob Agents Chemother ; 68(2): e0139323, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38169309

RESUMO

Aminoglycosides are important treatment options for serious lung infections, but modeling analyses to quantify their human lung epithelial lining fluid (ELF) penetration are lacking. We estimated the extent and rate of penetration for five aminoglycosides via population pharmacokinetics from eight published studies. The area under the curve in ELF vs plasma ranged from 50% to 100% and equilibration half-lives from 0.61 to 5.80 h, indicating extensive system hysteresis. Aminoglycoside ELF peak concentrations were blunted, but overall exposures were moderately high.


Assuntos
Aminoglicosídeos , Antibacterianos , Humanos , Antibacterianos/farmacocinética , Pulmão , Amicacina
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...